JPH09112656A - Differential device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To sufficiently lubricate a sliding portion between a side gear or a pinion gear and a differential case so that a stable differential limiting function can be obtained. SOLUTION: A differential case 21 and side gears 41, 4
3, pinion gears 63 and 64, and storage holes 61 and 62
And the boss portions 25 and 3 of the differential case 21 through which the output shaft passes.
5, the outer circumference of the output shaft and the boss portions 25, 3 of the differential case 21.
First oil passages 46, 4 formed between the inner circumference of
8 and the second oil passage 5 which is formed in the sliding portion between the end faces of the boss portions 51 and 53 of the side gears 41 and 43 and the differential case 21 and whose inner peripheral end communicates with the first oil passages 46 and 47.
8, 59 and boss portions 51, 53 of the side gears 41, 43
A third oil passage 52 that is formed on the outer circumference of the second oil passages 58 and 59 and communicates with the outer circumferential ends of the second oil passages 58 and 59.
It was configured with a spiral groove that was simultaneously processed as a tooth bottom at the time of gear cutting of 1 and 43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle differential device.

[0002]

2. Description of the Related Art Conventionally, a differential device as shown in FIG. 4 is known (see US Pat. No. 5,415,599). In this differential device 1, the driving force of the engine that rotates the differential case 3 is generated by the pinion gear 5,
7 is transmitted to wheels via output side gears 9 and 11. The pinion gears 5 and 7 are the storage holes 1 of the differential case 3.
3 and 15 are slidably and rotatably housed respectively. The pinion gears 5 and 7 and the side gears 9 and 11 are helical gears, respectively.

In the differential device 1, the pinion gears 5 and 7 are engaged with the side gears 9 and 11 while the torque is being transmitted.
Frictional resistance is generated by being pressed against the wall surface of 15, and frictional resistance is generated between the side gears 9 and 11 and between the respective gears 5, 7, 9 and 11 and the differential case 3 due to the meshing thrust force of the helical gear. The differential limiting force is obtained by these frictional resistances.

[0004]

In the differential device 1 described above, frictional resistance with the differential case 3 is generated by the meshing reaction force and meshing thrust force of the side gears 9 and 11 and the pinion gears 5 and 7 according to the input torque. Is generated and the differential limiting force is obtained, but the sliding portion between the outer circumferences of the pinion gears 5 and 7 and the inner circumferences of the housing holes 13 and 15, and
At the sliding portion between the end faces of the pinion gears 5 and 7 and the wall surface of the differential case 3, if the oil is not sufficiently introduced into the differential case 3, the oil will run out, seizure or galling will occur, and the differential limiting function will occur. There was a problem of becoming unstable.

In particular, when the side gears 9 and 11 and the pinion gears 5 and 7 are helical gears, the end faces of the pinion gears 5 and 7 are strongly pressed against the wall surface of the differential case 3 by the thrust force when a differential rotation occurs, so It is important to lubricate the above, but in the past, sufficient oil was not supplied, and problems such as seizure and galling occurred, and the differential limiting function might become unstable.

It is an object of the present invention to provide a differential device capable of obtaining a stable differential limiting function by sufficiently lubricating a sliding portion between a side gear or a pinion gear and a differential case.

[0007]

According to another aspect of the present invention, there is provided a differential device including a differential case which is disposed in an oil sump and is rotationally driven by an engine, and a differential case which is housed in the differential case and is rotatable about a common axis with the differential case. A pair of output side gears, which are arranged opposite to each other and whose end faces on the opposite side and the opposite side slide with the thrust case or directly with the differential case, are arranged on the outer peripheral side of the side gears and mesh with each other and separate side gears. At least a pair of pinion gears that mesh with the differential gear, at least a pair of storage holes that are formed in the differential case, and that store the respective pinion gears so as to be slidably rotatable about an axis parallel to the rotation axis of the differential case; and an output shaft connected to the side gear. The boss part of the differential case that penetrates, the outer periphery of the output shaft and the boss part of the differential case A first oil passage formed between the inner circumference and a second oil passage formed in a sliding portion between the end surface of the boss portion of the side gear and the differential case, and having an inner end communicating with the first oil passage. And a third oil passage formed on the outer periphery of the boss portion of the side gear and communicating with the outer peripheral end of the second oil passage.

In this differential device, the oil that has flowed into the differential case from the first oil passage in association with the rotation of the differential case enters the second oil passage and lubricates the boss end surface of the side gear and the sliding portion of the differential case. . In addition, the oil that has flowed into the second oil passage flows from the inner peripheral end of the second oil passage to the outer peripheral end thereof, reaches the third oil passage, and reaches the meshing portion of the pinion gear and the end surface of the pinion gear through the third passage. Supplied.

The invention according to claim 2 is the differential device according to claim 1, wherein the third oil passage is
It is characterized by a spiral groove that is simultaneously machined as a tooth bottom at the time of gear cutting of a side gear composed of a helical gear.

In this differential device, since the third oil passage is formed by the spiral groove on the outer periphery of the boss portion, when differential rotation occurs between the side gear and the differential case, the oil is positively acted on by the spiral groove due to the action of the spiral groove. It is supplied from the oil passage to the third oil passage side.

A third aspect of the present invention is the differential device according to the first or second aspect, wherein the first oil passage is formed on the inner circumference of the boss portion of the differential case, and the differential case rotates to move from the oil reservoir to the inside of the differential case. It is characterized by comprising a spiral groove having an inclination angle in the direction of introducing oil.

In this differential device, when the differential case rotates, oil is positively introduced into the differential case from the oil reservoir by the action of the spiral groove on the inner circumference of the boss portion of the differential case. Then, the second oil passage flows from the inner peripheral end to the outer peripheral end while receiving a centrifugal force, and is supplied to the meshing portion of the pinion gear and the end surface of the pinion gear through the third oil passage.

The invention of claim 4 is the differential device according to any one of claims 1 to 3, wherein the outer periphery of the end portion of the boss portion of the side gear is the inner periphery of a circular recess formed in the wall surface of the differential case. It is characterized in that the side gear is centered with respect to the differential case by being fitted to.

In this differential device, the outer circumference of the end portion of the side gear is fitted to the inner circumference of the circular recess of the differential case, and the third oil passage existing on the fitting surface and the second end portion of the end surface of the boss portion of the side gear. The oil flowing in from the first oil passage is always supplied to the outer peripheral side of the side gear through the oil passage.

The invention of claim 5 is the differential device according to any one of claims 1 to 4, wherein the differential device is the third device.
Is connected to a fourth oil passage formed in a sliding portion between the end face of the pinion gear and the differential case.

In this differential device, the fourth oil passage communicating with the third oil passage is formed at the sliding portion between the end face of the pinion gear and the differential case, so that the oil can be sufficiently supplied to the end face of the pinion gear.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of the differential device of the present embodiment, and FIG. 2 is a view taken in the direction of arrow I in FIG.

The differential device 2 of this embodiment
Reference numeral 0 has a differential case 21 that is driven to rotate about the axis L by the engine. The differential case 21 has a side wall portion 23.
And casing body 27 having cylindrical boss portion 25
And a cover 37 having a cylindrical boss portion 35.
The cover 37 is bolted to the casing body 27 so as to close the opening surface of the casing body 27 on the side opposite to the side wall portion 23. Inside the differential case 21, left and right output side gears 41, 43 are arranged rotatably opposite to each other coaxially with the axis L. Side gear 41 on the left in the figure
Has its end outer periphery fitted to the inner periphery of the circular recess 47 formed on the inner periphery of the boss portion 35 of the cover 37, so that it is centered with respect to the axis L, and the side gear 43 on the right side in the figure.
Is the boss portion 25 of the casing body 27.
By being fitted to the inner circumference of the circular recess 49 formed on the inner circumference of, the shaft is centered with respect to the axis L.

The left side gear 41 in the figure is splined to a left output shaft (not shown) by a boss portion 51, and the right side gear 43 is splined to a right output shaft (not shown) by a boss portion 53. Each output shaft (rotary shaft) is provided so as to penetrate the boss portion 35 of the cover 37 and the boss portion 25 of the casing body 27. Boss part 3 of cover 37
5 and spiral grooves 46 and 48 as first oil passages are formed on the inner circumference of the boss portion 25 of the casing body 27. The spiral grooves 46 and 48 are provided with an inclination angle θ in a direction in which the oil is introduced into the differential case 21 from the oil reservoir by the rotation of the differential case 21.

Further, the boss portion 5 of the side gears 41 and 43
A washer 55, between the end surfaces (outer end surfaces) of the first and the third 53 and the inner surfaces of the circular recesses 47 and 49 of the differential case 21.
57, the end faces of the boss portions 51, 53 of the side gears 41, 43 slide on the differential case 21 via the washers 55, 57 when an outward thrust force acts on the side gears 41, 43. ing. Boss part 5
The inner end faces (opposing faces) of the first and the third 53 are in contact with each other.

Also, the side gear 4 used here
As shown in FIG. 3, the Nos. 1 and 43 have spiral grooves 52 as third oil passages on the outer circumferences of the bosses 51 and 53. The spiral groove 52 is formed as a tooth bottom at the time of cutting the side gears 41 and 43, which are helical gears, and is continuously formed up to the end surfaces of the boss portions 51 and 53.

Further, the boss portion 5 of the side gears 41 and 43
In the portion where the end faces of 1, 53 and the wall surface of the differential case 21 slide through the thrust washers 55, 57, the second
Oil grooves 58, 59 as oil passages are formed. These oil grooves 58, 59 extend radially from the inner peripheral side toward the outer peripheral side, and a plurality of oil grooves 58, 59 are provided at equal intervals in the circumferential direction. Further, the oil grooves 58, 59 communicate with the spiral grooves (first oil passages) 46, 48 on the inner circumference of the boss portions 25, 35 of the differential case 21 at the inner peripheral ends thereof, and the side gears 41, 43 have outer peripheral ends thereof. It communicates with the spiral groove 52 on the outer circumference of the boss portions 51 and 53.

In this embodiment, the oil groove 5 on the left side of the drawing is
8 is formed on the end surface of the boss portion 51 of the side gear 41,
The oil groove 59 on the right side in the drawing is formed on the wall surface of the differential case 21. The side on which the oil grooves 58 and 59 are formed (the end surface side of the side gear or the wall surface side of the differential case) may be opposite to that shown in the figure, or both sides (the end surface side of the side gear or the wall surface side of the differential case). May be aligned with. That is, both oil grooves may be formed on the end surface of the side gear or on the wall surface of the differential case. It is also possible to do so if it can be formed into a thrust washer.

Further, as shown in FIG. 2, the differential case 21 is provided with a plurality of sets (a plurality of sets) of storage holes 61 and 62, which are formed in pairs. Storage holes 61, 6
The pinion gears 63 and 64 are housed in 2 respectively so as to be slidably rotatable. Pinion gears 63, 64 in this case
Have the same shape and are simply inserted in the storage holes 61 and 62 in opposite directions. The side gears 41, 43,
The gear portions of the pinion gears 63 and 64 are helical gears.

The pinion gears 63 and 64 are composed of first and second gear portions 65 and 66 and a small diameter shaft portion 67 connecting them. The first gear portion 65 of the one pinion gear 63 (upper side in the drawing) meshes with the left side gear 41. Further, the first gear portion 65 of the other pinion gear 64 accommodated in the opposite direction meshes with the right side gear 43. The first gear portion 65 and the second gear portion 66 of both the pinion gears 63 and 64 mesh with each other. The mutual meshing portions are both axial ends of the pinion gears 63 and 64, and the meshing portions of the pinion gears 63 and 64 and the side gears 41 and 43 are located between the mutual meshing portions.

The pinion gears 63, 64 are provided on both end faces with center holes 75 as chuck holes for lathe machining. Further, the inner surface of the side wall portion 23 of the casing body 27 and the inner surface of the cover 37 (sliding surfaces of the pinion gears 63 and 64) are made to correspond to the positions of the storage holes 61 and 62 of the differential case 21 that store the pinion gears 61 and 62.
An oil groove (fourth oil passage) 77 extending in the radial direction of the differential case 21 is formed in the. The oil groove 77 communicates with the spiral groove 52 on the outer periphery of the boss portions 51 and 53 of the side gears 41 and 43.

In the differential device of this embodiment, the driving force of the engine for rotating the differential case 21 is
When the pinion gears 63 and 64 are distributed to the left and right output sides via the side gears 41 and 43, and a driving resistance difference is generated between the output sides, the rotation of the pinion gears 63 and 64 causes the engine driving force to be differentially distributed to the left and right parts. It

While transmitting the torque, the pinion gear 6
3 and 64 are pressed against the wall surfaces of the storage holes 61 and 62 by the reaction force of meshing with the side gears 41 and 43 to generate frictional resistance, and the meshing thrust force of the helical gears causes the end faces of the pinion gears 63 and 64 and the side gear 4 to rotate.
Friction resistance occurs between the end faces of Nos. 1 and 43 and the differential case 21, and between the side gears 41 and 43. A torque-sensitive differential limiting function is obtained by these frictional resistances that increase in proportion to the transmission torque.

When the differential case 21 rotates during this differential operation, the oil splashed from the oil reservoir of the differential carrier (not shown) by the ring gear (not shown) is removed.
It flows into and out of the differential case 21 through an opening (not shown) in the differential case 21 and spiral grooves 46, 48 between the boss portions 25, 35 of the differential case 21 and the output shaft. In particular, from the spiral grooves 46 and 48 which are the first oil passages, during differential rotation,
Oil is positively introduced by the pumping action of the spiral.

The oil that has flowed in from the spiral grooves 46 and 48 is absorbed by the end faces of the side gears 41 and 43 and the differential case 2.
Oil groove (second oil passage) 5 secured between 1 and
8, 59, and the boss portion 41 of the side gears 41, 43,
The spiral groove 52 formed on the outer periphery of the 53 is positively guided to the outer peripheral side of the side gears 41 and 43. As a result, not only the end faces of the side gears 41 and 43 but also the pinion gears 63 and 64
Sufficient oil is spread to the mutual meshing portions of the above and the meshing portions of the pinion gears 63 and 64 and the side gears 41 and 43. Further, by the action of the spiral groove 52 on the outer periphery of the boss portions 51, 53 of the side gears 41, 43, the pinion gears 63, 64
Groove 77 on the sliding part between the end surface of the differential case and the differential case 21
Also, sufficient oil is supplied, and as a result, the sliding portions on the end surfaces of the pinion gears 63 and 64 are well lubricated.

In this case, the outer peripheries of the end portions of the side gears 41 and 43 are formed by the centering of the side gears 41 and 43.
Although it is closely fitted to the inner circumferences of the circular recesses 47, 49 of the differential case 21, there is a risk of oil being cut off there, but spirals as a third oil passage are provided on the outer circumferences of the boss portions 51, 53 of the side gears 41, 43. Since there is the groove 52, the oil is connected and flows, and a sufficient amount of oil is also supplied to the pinion gears 63 and 64.

The positions where the various oil grooves are provided can be changed as long as they do not violate their functions. For example,
The spiral grooves 46 and 48 as the first oil passages may be provided not on the inner peripheral side of the boss portions 25, 35 but on the outer peripheral side of the output shaft. The oil groove 77 as the fourth oil passage may be provided on the end faces of the pinion gears 63 and 64.

[0034]

As described above, according to the first aspect of the invention, the first oil passage is provided between the outer circumference of the output shaft and the inner circumference of the boss, and the boss end surface of the side gear and the differential case are provided. A second oil passage, the inner peripheral end of which communicates with the first oil passage, is provided at the sliding portion of the, and the outer periphery of the boss portion of the side gear is
Since the third oil passage that communicates with the outer peripheral end of the second oil passage is provided, the oil that has flowed into the differential case from the first oil passage due to the rotation of the differential case is transferred from the second oil passage to the side gear. It can be supplied to the end face of the boss. In addition, the oil flowing into the second oil passage is
It can be supplied to the meshing portion of the pinion gear and the end surface of the pinion gear through the third passage. Therefore, it is possible to supply sufficient oil to the meshing parts and sliding parts of the gear, especially to the end surface of the pinion gear during differential rotation, prevent seizure and abnormal noise, and achieve a stable differential limiting function. Can be obtained.

According to the second aspect of the invention, since the third oil passage is constituted by the spiral groove, when the differential rotation occurs between the side gear and the differential case, the action of the spiral groove positively moves the oil into the second oil passage. Can be supplied to the side of the third oil passage. Therefore, a sufficient amount of oil can be supplied to the meshing portion of the pinion gear and the end surface of the pinion gear, and a more stable differential limiting function can be obtained. Further, since the spiral groove, which is the third oil passage, is machined at the same time when gear cutting of the side gear, there is no particular increase in machining cost.

According to the third aspect of the present invention, the first oil passage is constituted by the spiral groove on the inner circumference of the boss portion of the differential case. Therefore, the spiral groove acts in accordance with the rotation of the differential case, and the positive oil is positively discharged from the oil reservoir. Oil can be introduced into the differential case. Therefore, sufficient oil can be supplied to the meshing portion of the pinion gear and the end surface of the pinion gear through the second oil passage and the third oil passage, and seizure can be prevented to obtain a stable differential limiting function. You can

According to the fourth aspect of the invention, the outer circumference of the end of the boss portion of the side gear is fitted to the inner circumference of the circular recess of the differential case for centering. The third oil passage is provided on the fitting surface. Since it exists, the oil from the second oil passage can be guided to the outer peripheral side of the side gear through the third oil passage. Therefore, the oil guided to the outer peripheral side of the side gear can sufficiently lubricate the sliding portion between the end surface of the pinion gear and the differential case.

According to the fifth aspect of the present invention, the fourth oil passage communicating with the third oil passage is formed at the sliding portion between the end face of the pinion gear and the differential case, so that the oil can be sufficiently supplied to the end face of the pinion gear. It is possible to prevent the seizure and the generation of abnormal noise at the sliding portion, and to obtain a stable differential limiting function.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a view on arrow I of FIG.

FIG. 3 is a perspective view of a side gear according to the embodiment of the present invention.

FIG. 4 is a sectional view of a conventional example.

[Explanation of symbols]

 20 differential device 21 differential case 25, 35 differential case boss portion 41, 43 side gear 46, 48 spiral groove (first oil passage) 47, 49 circular recess 51, 53 side gear boss portion 52 spiral groove (third oil passage) 55,57 Thrust washer 58,59 Oil groove (second oil passage) 61,62 Storage hole 63,64 Pinion gear 77 Oil groove (fourth oil passage) L axis

Claims (5)

[Claims] 1. A differential case, which is disposed in an oil sump and is driven to rotate by an engine, and a differential case, which is housed in the differential case and is rotatably opposed to the differential case about a common axis, and opposite to the opposite side. A pair of output side gears that slide with the thrust case or directly with the differential case, and at least one pair of pinion gears that are arranged on the outer peripheral side of the side gears and that mesh with each other and each of the side gears, and the differential case. At least a pair of storage holes for storing each pinion gear so as to be slidably rotatable about an axis parallel to the rotation axis of the differential case, a boss case of the differential case through which the output shaft connected to the side gear passes, and an outer circumference of the output shaft. A first oil passage formed between the inner periphery of the boss portion of the differential case and A second oil passage formed on a sliding portion between the end surface of the boss portion of the gear and the differential case and having an inner peripheral end communicating with the first oil passage; and a second oil passage formed on the outer periphery of the boss portion of the side gear. A differential device comprising a third oil passage communicating with an outer peripheral end of the passage. 2. The differential device according to claim 1, wherein the third oil passage comprises a spiral groove that is simultaneously machined as a tooth bottom when gear cutting of a side gear made of a helical gear. Differential device. 3. The differential device according to claim 1, wherein the first oil passage is formed in an inner circumference of a boss portion of the differential case, and oil is introduced into the differential case from the oil reservoir by rotation of the differential case. A differential device comprising a spiral groove having an inclined angle in a direction. 4. The differential device according to claim 1, wherein an outer circumference of an end portion of the boss portion of the side gear is fitted to an inner circumference of a circular recess formed in a wall surface of the differential case. By that,
A differential device in which the side gear is centered with respect to the differential case. 5. The differential device according to claim 1, wherein the third oil passage is formed in a sliding portion between an end surface of the pinion gear and a differential case. The differential device is characterized by being communicated with.